Hi
I'm trying to decide what spoke length I should use.

The Non-Drive side needs 278.3mm and Drive side is 276.3mm. Could I just buy 278mm spokes for both sides?

It's a 90's Zipp Ballistic Hub and a Kinlin XR-200 rim ERD594. 1x on both sides. 28 holes.
I have attached the spoke calculator image for all the details.

And this is the data I found for the hub measurements: http://www.zipp.com/support/identify/hub_timeline.php